<?php

namespace LIBS;

class DES {
  var $key;
  var $iv; //偏移量

  function GetKey($key) {
    $tmp = "--------";
    $key = substr ( $key . $tmp, 0, 8 );
    return $key;
  }
  function DES($key, $iv = 0) {

    //key长度8例如:1234abcd
    $this->key =$this->GetKey($key);
    if ($iv == 0) {
      $this->iv = $this->key;
    } else {
      $this->iv = $iv; //mcrypt_create_iv ( mcrypt_get_block_size (MCRYPT_DES, MCRYPT_MODE_CBC), MCRYPT_DEV_RANDOM );
    }
  }

  function encrypt($str) {
    //加密，返回大写十六进制字符串
    $size = @mcrypt_get_block_size ( MCRYPT_DES, MCRYPT_MODE_CBC );
    $str = $this->pkcs5Pad ( $str, $size );
    return strtoupper ( bin2hex ( @mcrypt_encrypt ( MCRYPT_DES, $this->key, $str, MCRYPT_MODE_CBC, $this->iv ) ) );
  }

  function decrypt($str) {
    //解密
    $strBin = $this->hex2bin ( strtolower ( $str ) );
    $str = @mcrypt_decrypt ( MCRYPT_DES, $this->key, $strBin, MCRYPT_MODE_CBC, $this->iv );
    $str = $this->pkcs5Unpad ( $str );
    return $str;
  }

  function hex2bin($hexData) {
    $binData = "";
    for($i = 0; $i < strlen ( $hexData ); $i += 2) {
      $binData .= chr ( hexdec ( substr ( $hexData, $i, 2 ) ) );
    }
    return $binData;
  }

  function pkcs5Pad($text, $blocksize) {
    $pad = $blocksize - (strlen ( $text ) % $blocksize);
    return $text . str_repeat ( chr ( $pad ), $pad );
  }

  function pkcs5Unpad($text) {
    $pad = ord ( $text {strlen ( $text ) - 1} );
    if ($pad > strlen ( $text ))
      return false;
    if (strspn ( $text, chr ( $pad ), strlen ( $text ) - $pad ) != $pad)
      return false;
    return substr ( $text, 0, - 1 * $pad );
  }

}

?>
